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1.
Poly(o-methoxyaniline) (POMA) salts doped with organic sulphonic acids (methanesulphonic acid, p-toluenesulphonic acid and dodecylbenzenesulphonic acid) were firstly synthesized by using solid-state polymerization method. The polymers were characterized by Fourier transform Infrared (FTIR) spectra, ultraviolet visible (UV–vis) spectrometry, X-ray diffraction (XRD), Cyclic Voltammetry (CV), and conductivity measurements. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were done to study the morphologies of POMA salts. The results showed that the POMA doped with methanesulphonic acid displayed higher doping level and conductivity. On the contrary, POMA doped with dodecylbenzenesulphonic acid was lower at doping level and conductivity. In accordance with these results, the electrochemical activity was also found to be lower in dodecylbenzenesulphonic acid doped POMA. The results also revealed that the particles of POMA salts have the average size of less than 100 nm.  相似文献   

2.
In the present work, the doped (composite) films of póly(o-anisidine)–polyvinylsulphonic acid (POA-PVS), poly(o-anisidine)–toluenesulphonic acid (POA-pTS), and poly(o-anisidine)–dodecylbenzenesulphonic acid (POA-DBS) were synthesized on a platinum electrode, using electrochemical polymerization. These synthesized films were characterized by electrochemical techniques, conductivity measurement, UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The optimal film growth was achieved for synthesis of the POA film in the presence of dodecylbenzenesulphonic acid (DBS). The POA-DBS composite film exhibits good electrochemical properties, conductivity with a uniformly porous surface morphology which can be used for the immobilization of biocomponent.  相似文献   

3.
Poly (o‐toluidine) (POT) salts doped with organic sulfonic acids (β‐naphthalene sulfonic acid, camphor sulfonic acid, and p‐toluene sulfonic acid) were directly synthesized by using a new solid‐state polymerization method. The FTIR spectra, ultraviolet visibility (UV–vis) absorption spectra, and X‐ray diffraction patterns were used to characterize the molecular structures of the POT salts. Voltammetric study was done to investigate the electrochemical behaviors of all these POT salts. The FTIR and UV–vis absorption spectra revealed that the POT salts were composed of mixed oxidation state phases. All POT salts contained the conducting emeraldine salt (half‐oxidized and protonated form) phase; the pernigraniline (fully oxidized form) phase is predominant in POT doped with β‐naphthalene sulfonic acid, and POT doped with p‐toluene sulfonic acid had the highest doping level. The X‐ray diffraction patterns showed that the obtained POT doped with organic sulfonic acids were lower at crystallinity. The conductivity of the POT salts were found to be of the order 10?3‐10?4 S/cm. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1630–1634, 2005  相似文献   

4.
Polyaniline (PANI) salts doped with hydrochloric acid were prepared by using solid‐state polymerization in the presence of β‐cyclodextrin (β‐CD) at room temperature. The fourier transform infrared (FTIR) spectra, ultraviolet‐visible absorption spectra, X‐ray diffraction patterns were used to characterize the molecular structures of these polymers. Cyclic voltammetry study and conductivity measurements were done to investigate their electrochemical behaviors. The morphology of polymers was studied by the scanning electron microscopy and transmission electron microscopy. The results showed that PANI salts prepared in the presence of β‐CD had different physicochemical characteristics compared with PANI salt prepared in the absence of β‐CD. When the molar ratio of aniline to β‐CD was 80/20, the obtained PANI salt displayed higher crystallinity, conductivity and electrochemical properties. However, these properties were opposite on condition that the molar ratio of aniline to β‐CD was 50/50. The results also revealed that the morphology of PANI salt was affected by β‐CD, especially at aniline/β‐CD molar ratio in the feed of 50/50, in which PANI salt displayed rodlike structure morphology with a diameter of near 80–100 nm. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

5.
A series of novel soluble and thermoplastic polyurethane/polyaniline (TPU/PANI) composites doped with a compound acid, which was composed of an organic acid (p‐toluene sulfonic acid) and an inorganic acid (phosphoric acid), were successfully prepared by in situ polymerization. The effect of aniline (ANI) content, ratio of organic acid/inorganic acid, and different preparation methods on the conductivity of the TPU/PANI composites were investigated by using conductivity measurement. Lithium bisoxalato borate (LiBOB) was added to the prepared in situ TPU/PANI to coordinate with the ether oxygen groups originating from the soft molecular chains of TPU, and thus the conductivity of the composites was further enhanced. The molecular structure, thermal properties, and morphology of the TPU/PANI composites were studied by UV–visible spectroscopy, differential scanning calorimetry, and scanning electron microscopy, respectively. The results show that the in situ TPU/PANI composites doped with the compound acid can be easily dissolved in normal solvents such as dimethylformamide (DMF) and 1,4‐dioxane. The conductivity of the TPU/PANI composites increases with the increase of the ANI content, in the ANI content range of 0–20 wt %; however, the conductivity of the composites reduces with further increment of ANI content. The conductivity of the TPU/PANI composites prepared by in situ polymerization is about two orders of magnitude higher than that prepared by solution blending method. LiBOB can endow the in situ TPU/PANI composites with an ionic conductivity. The dependence of the conductivity on temperature is in good accordance with the Arrhenius equation in the temperature range of 20–80°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

6.
The effects of dopant type, doping level, polyimide (PI) content and temperature on electrical conductivity response of polyaniline (PANI) and polyaniline/polyimide (PANI/PI) blends to CO–N2 gas mixtures were systematically investigated. At the same doping level, HNO3‐doped PANI has a greater electrical conductivity response and sensitivity towards CO than that of camphor sulfonic acid (CSA)‐doped PANI because the former has a more ordered structure. The interaction mechanism between CO and PANI is proposed to occur at the attack site, ? N?H? or the amine nitrogen where CO withdraws an electron. Addition of PI causes a small change in electrical conductivity under atmospheric conditions when PI content is below the percolation threshold value of 55 wt%. Addition of PI reduces brittleness and improves electrical conductivity sensitivity towards CO; the effect is more pronounced at higher temperatures. Copyright © 2005 Society of Chemical Industry  相似文献   

7.
Stability, including thermal stability, conductivity stability in air and after thermal treatment (100–200°C), of the polyaniline (PANI) films synthesized by a doping–dedoping–redoping method was investigated. It was found that thermogravimetric analysis (TGA) curves undergo three steps: loss of water or solvent, dedoping and decomposition, and those depend on the counterions. Compared with PANI films doped with camphor sulfonic acid (CSA) in m‐cresol, the thermal stability of the doped PANI films is improved by the new method, and thermal stability in the order of PANI–H3PO4 > PANI–p‐TSA > PANI–H2SO4 > PANI–HCl, PANI–HClO4 > PANI–CSA was observed. The conductivity of the doped PANI films at room temperature was reduced after thermal treatment, and it is dependent of the counterions. It was found that the conductivity stability of PANI–p‐TSA and PANI–CSA is the best below 200°C. When the doped PANI films were placed in air, their conductivity decrease slowly with time due to deproton, and also depends on the counterions. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 615–621, 1999  相似文献   

8.
Highly crystalline camphor sulfonic acid (CSA)‐doped polyaniline (PANI) thin films cast from m‐cresol and N‐methylpyrrolidone (NMP) were investigated. PANI powder prepared by chemical oxidative polymerization subjected to doping–de‐doping–re‐doping procedures was cast into thin films using NMP and m‐cresol as solvents. X‐ray diffraction (XRD) reveals the presence of exceptionally highly crystalline or rather ordered regions in the PANI film samples prepared from m‐cresol. Atomic force microscopy (AFM) images also support the presence of crystalline regions on the surface of these films. The DC electrical conductivity of m‐cresol‐cast PANI is found to be quite high, and much higher than that of NMP‐cast PANI. The free‐carrier absorption tail extending to the near‐infrared region observed in the optical absorption spectrum of the m‐cresol‐cast PANI films suggests a metallic nature and regular structural arrangement in these films. Both inter‐chain and intra‐chain ordering brought about as a result of CSA doping, secondary doping effect of m‐cresol and ultrasonication are suggested to be the prime factors contributing towards the observed excellent crystallinity of these PANI films as evident from the XRD and AFM studies. The marked thermal stability of the m‐cresol‐cast PANI films is also established based on the variation of DC electrical conductivity with temperature and on thermogravimetric analysis. Copyright © 2012 Society of Chemical Industry  相似文献   

9.
Copolymer of aniline and pyrrole was synthesized by inverted emulsion polymerization method by oxidizing aniline and pyrrole using benzoyl peroxide in presence of sodium laurylsulphate surfactant and p‐toluenesulphonic acid. Copolymer samples were characterized by infrared, X‐ray diffraction and scanning electron microscopic techniques and compared their properties with the corresponding homopolymers. The optimum reaction conditions for the preparation of copolymer with reasonably good yield (1.72 g) and conductivity (7.3 × 10?2 S/cm) were established. The synthesis procedure was extended to prepare copolymer samples using various protonic acids. Electrochemical characterization such as cyclic voltammetry, charge‐discharge and impedance were carried out on symmetrical supercapacitor cell consists of poly(aniline‐co‐pyrrole)‐p‐toluenesulfonic acid salt, wherein, the copolymer salt was synthesized using equal amount of aniline and pyrrole monomers. The values of specific capacitance, energy and power densities for poly(aniline‐co‐pyrrole)‐p‐toluenesulfonic acid system (PANI‐PPy) were calculated from charge‐discharge studies and are found to be 21 F/g, 5.7 Wh/Kg and 100 W/Kg respectively. Impedance analysis showed specific capacitance value (57 F/g) at 0.01 Hz at 0.22 V. Among the copolymer salts, copolymer prepared with sulfuric acid showed higher capacitance (66 F/g). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

10.
Self‐doped poly(aniline‐co‐aminonaphthalene sulfonic acid) (PANI‐ANSA) was synthesized by the copolymerization of 5‐aminonaphthalene‐2‐sulfonic acid (ANSA) and aniline. Scanning electron microscopy and transmission electron microscopy showed that the morphology of PANI‐ANSA synthesized at a high molar ratio of aniline to ANSA was nanotubular, but at a low molar ratio, only a granular morphology formed. A possible formation mechanism for nanotubes was proposed. PANI‐ANSA had better thermal stability than HCl‐doped polyaniline; the highest onset decomposition temperature was as high as 340°C because of ? SO3H linked with the polymer backbone by a covalent bond. PANI‐ANSA was partially soluble in basic solutions, and its conductivity was between 10?2 and 10?4 S/cm, depending on the sulfonation degree. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1297–1301, 2003  相似文献   

11.
Electrically conductive polyaniline (PANI)/[poly(m‐phenylene isophthalamide)] Nomex composite fabric was prepared by in situ polymerization of aniline doped by a mixture of hydrochloride (HCl) and various sulfonic acids such as benzenesulfonic acid (BSA), sulfosalicylic acid (SSA), and dodecylbenesulfonic acid (DBSA); their effect on conductivity and physical properties were then investigated. PANI/Nomex composite fabrics doped by a mixture of protonic acids exhibited higher conductivity than those doped by other single dopants such as camphorsulfonic acid (CSA), p‐toluenesulfonic acid (TSA), BSA, SSA, and HCl. The conductivity of PANI/Nomex fabrics especially doped by a mixture of HCl and DBSA was evenly maintained up to 100°C without depression of mechanical properties of Nomex. Their conductivity was also maintained under extension of the composite fabric. In addition, electrical conductivity of PANI/Nomex fabrics was highly increased by ultrasonic treatment, which facilitated better diffusion and adsorption of aniline by cavitation and vibration. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2245–2254, 2002  相似文献   

12.
The electrochemical synthesis of polyaniline (PAni) powder was carried out from an aqueous solution of 0.15 mol L?1 aniline with varying concentrations of p‐toluenesulphonic acid (PTSA) at room temperature. The PAni samples thus obtained were characterized using DC and AC conductivity, dielectric properties, infrared spectroscopy, thermogravimetric analysis, X‐ray analysis, scanning electron microscopy and ultraviolet spectroscopy. Results showed that PTSA is acting both as electrolyte and doping agent. With an increase in the PTSA concentration, there is more polaron formation, and this means an increase in charge carrier concentration and mobility. This accounts for the increase in conductivity and improved dielectric properties of the resultant PAni. The polymer was subjected to a heating and cooling cycle. The change in conductivity during the heating cycle is quite different from that during the cooling cycle, indicating some kind of hysteresis phenomenon occurring in the system. Moreover there is a net decrease in room temperature conductivity of PAni when subjected to the heating–cooling cycle. This may be due to the oxidation of PAni and generation of some kind of disorder in the structure of PAni during the heating–cooling process. Copyright © 2007 Society of Chemical Industry  相似文献   

13.
Electrically conducting elastomer fibers based on natural rubber (NR) and up to 10% w/w polyaniline (PANI) in its emeraldine base (EB) form were fabricated by a wet spinning process. The resulting fibers at various PANI contents were doped by immersion in aqueous HCl solution, which converted the PANI to the electrically conductive emeraldine salt (ES) form. The morphology of the composite fibers was studied by scanning electron microscopy (SEM). PANI particles were inhomogeneously distributed in the NR matrix. The electrical conductivity of the fibers increased with the increasing PANI‐ES content and leveled off at a value of around 10?3 S/cm at PANI‐ES concentration of 5% w/w. The fibers retained most of their elasticity upon doping, while the tenacity was somewhat reduced. Gratifyingly, the electrical conductivity of the new elastomer fibers was preserved upon elongational deformation, even if strains as large as 600% were applied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007  相似文献   

14.
Polyaniline (PANI) was doped with five novel dopants, 3‐pentadecylphenylphosphoric acid (PDPPA), pentadecylphenyl(bis)phosphoric acid [PDP(bis)PA], monocardanylphosphoric acid (MCPA), dicardanylphosphoric acid (DCPA), and phosphorylated cashew nut shell liquid prepolymer (PCNSL) and the doping behavior was studied. All dopants were synthesized from inexpensive naturally existing monomers [obtained from cashew nut shell liquid (CNSL)] having a long hydrophobic hydrocarbon side chain in the meta position of the aromatic ring. These dopants can act as plasticizing cum protonating agents for PANI so that free‐standing films of PANI could be prepared by both thermal processing and solution processing techniques. Protonation was performed either by mechanical mixing of emeraldine base and the dopant or by an in situ doping emulsion polymerization route using xylene or chloroform as the solvent. Further, conductive flexible blends of the protonated PANI with poly(vinyl chloride) (PVC) were also prepared and studied for their conductivity and related properties. The PANI–PDPPA complex obtained by the in situ doping emulsion polymerization route exhibited an exceptionally high degree of crystalline order and orientation. A maximum conductivity value of 1.8 S cm?1 was obtained for a PANI–PDPPA film hot‐pressed at 120°C. On the other hand, dopants based on cardanol having an unsaturated side chain gave only lower values. This was understood to be due the capability of the saturated analog to contribute to the ordered arrangement of PANI, thus improving the crystallinity. The conductivity values further decreased when bulky/oligomeric dopants such as PCNSL were used. The thermoplastic blends with PVC exhibited an exceptionally low‐level percolation threshold because of the plasticizing nature of the dopants. The doped polymers and blends were characterized by FTIR and UV‐visible spectroscopic methods, four‐probe conductivity measurements, XRD, SEM, TGA, and DSC. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1354–1367, 2001  相似文献   

15.
Polyaniline (PANI), poly(o‐anisidine), and poly[aniline‐co‐(o‐anisidine)] were synthesized by chemical oxidative polymerization with ammonium persulfate as an oxidizing reagent in an HCl medium. The viscosities, electrical conductivity, and crystallinity of the resulting polymers (self‐doped forms) were compared with those of the doped and undoped forms. The self‐doped, doped, and undoped forms of these polymers were characterized with infrared spectroscopy, ultraviolet–visible spectroscopy, and a four‐point‐probe conductivity method. X‐ray diffraction characterization revealed the crystalline nature of the polymers. The observed decrease in the conductivity of the copolymer and poly(o‐anisidine) with respect to PANI was attributed to the incorporation of the methoxy moieties into the PANI chain. The homopolymers attained conductivity in the range of 3.97 × 10?3 to 7.8 S/cm after doping with HCl. The conductivity of the undoped forms of the poly[aniline‐co‐(o‐anisidine)] and poly(o‐anisidine) was observed to be lower than 10?5 J/S cm?1. The conductivity of the studied polymer forms decreased by the doping process in the following order: self‐doped → doped → undoped. The conductivity of the studied polymers decreased by the monomer species in the following order: PANI → poly[aniline‐co‐(o‐anisidine)] → poly(o‐anisidine). All the polymer samples were largely amorphous, but with the attachment of the pendant groups of anisidine to the polymer system, the crystallinity region increased. The undoped form of poly[aniline‐co‐(o‐anisidine)] had good solubility in common organic solvents, whereas doped poly[aniline‐co‐(o‐anisidine)] was moderately crystalline and exhibited higher conductivity than the anisidine homopolymer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006  相似文献   

16.
Composites produced during the in situ chemical polymerization of aniline on top of a poly(ethylene terephthalate) (PET) film, in different conditions, were studied by open‐circuit potential (Voc), ultraviolet‐visible, and infrared spectroscopy, electrical conductivity measurements, scanning electron microscopy, and atomic force microscopy. The polymerization monitoring by Voc showed a maximum associated with the intermediate pernigraniline oxidation state and a final formation of polyaniline (PANI) in the doped emeraldine salt (ES) form. Furthermore, high electrical conductivity values were obtained for the PANI–ES coating prepared under selected conditions. A globular formation was observed for the doped PANI–ES coating with globules of sizes of the same order and same shape of the PET, demonstrating the influence of the substrate on the coating morphology. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1220–1229, 2001  相似文献   

17.
One‐dimensional nanostructures of polyaniline (PANI) doped with (1S)‐(+)‐10‐camphorsulfonic acid (D‐CSA) alone and with NiCl2 as a codopant were synthesized via in situ polymerization. PANI nanofibers with diameters of about 200 nm were formed when PANI was doped with D‐CSA only. When NiCl2 was added as a codopant, the morphology of PANI obviously changed. The effects and related mechanisms were investigated by Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, inductively coupled plasma–atomic emission spectroscopy, and X‐ray diffraction, and the results indicated that Ni2+ destroyed the micelles' structure by chemical conjunction with ? SO3H groups in camphorsulfonic acid (CSA) molecules, which were the key component in forming the CSA–aniline micelles. The combination between Ni2+ and SO in CSA with a lower addition of Ni2+ led to a reduction of CSA doping to PANI, but a higher loading of Ni2+ brought about the direct doping of Ni2+ to PANI, which caused a higher degree of doping and oxidation. The conductivity of PANI increased almost linearly with increasing Ni2+. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

18.
Polyaniline (PANI) with high crystallinity degree was facilely synthesized on the surface of stainless steel net by galvanostatic method. The effect of polymerization current density on the characteristics of morphology and structure had been investigated by field emission scanning electron microscopy (FE‐SEM), Fourier transforms infrared (FTIR), X‐ray photoelectron spectroscopy (XPS), and X‐ray diffraction (XRD). FE‐SEM observations disclosed that PANI was deposited as nanofibers and their diameters decreased with the polymerization current density. FTIR studies revealed that degree of oxidation increased in order PANI‐2 < PANI‐6 < PANI‐10. XPS measurements displayed that PANI polymerized at 6 mA cm?2 (PANI‐6) exhibited much higher doping level of 77.8%, which favored the conductivity. XRD analysis discovered that the obtained PANI showed high crystallinity degree in which PANI‐6 possessed highest crystallinity degree (Xcr) up to 67%. Electrochemical performances of PANI as electrode materials were studied via cyclic voltammetry. The results presented that PANI‐6 possessed greater discharge capacity and better reversibility. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40827.  相似文献   

19.
The present work describes the synthesis of conductive composite of polyurethane sulphonate anionomer (PUSA) and para toluene sulphonic acid doped polyaniline (PANI–PTSA). HCl‐doped PANI was synthesized by chemical oxidative polymerization of aniline in HCl, which was converted to PANI–EB by treatment with NH4OH. PTSA doped PANI was synthesized from EB‐PANI by redoping with PTSA solution. PUSA was synthesized from 4, 4′‐diphenylmethanediisocyanate (MDI), polypropylene glycol (PPG), 1,4‐butanediol (BD), and ionic diol SDOL. The composite was prepared by mixing of the solutions of two polymer components in DMF and then solution casting. The products were characterized and analyzed by UV‐Vis and FTIR spectroscopy, thermogravimetry, differential scanning calorimetry and scanning electron microscopy. The conductivity was found to increase by 100 times with concomitant decrease in percolation threshold when polyurethane was replaced by PUSA in the composite for the same amount of polyaniline. The composite film was thermally stable upto ~300°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41600.  相似文献   

20.
Polyaniline (PANI)/multiwalled carbon nanotube (MWNT) composites with a uniform tubular structure were prepared from in situ polymerization by dissolving amino‐functionalized MWNT (a‐MWNT) in aniline monomer. For this the oxidized multiwalled nanotube was functionalized with ethylenediamine, which provided ethylenediamine functional group on the MWNT surface confirmed by Fourier‐transform infrared spectra (FT‐IR). The a‐MWNT was dissolved in aniline monomer, and the in situ polymerization of aniline in the presence of these well dispersed nanotubes yielded a novel tubular composite of carbon nanotube having an ordered uniform encapsulation of doped polyaniline. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed that the nanotubes were coated with a PANI layer. The thermal stability and electrical conductivity of the PANI /MWNTs composites were characterized by thermogravimetric analysis (TGA) and conventional four‐probe method respectively. Compared with pure PANI, the electrical conductivity and the decomposition temperature of the MWNTs/PANI composites increased with the enhancement of MWNT content in PANI matrix. POLYM. COMPOS., 34:1119–1125, 2013. © 2013 Society of Plastics Engineers  相似文献   

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